var Camera = function(aCanvas, aContext, x, y) {
  var camera = this;

  var canvas = aCanvas;
  var context = aContext;

  var orion_image = new Image();
  var satellite_image = new Image();
  var wall_image = new Image();

  var earth_image = new Image();
  var moon_image = new Image();
  var mars_image = new Image();
  
  var skul_img1 = new Image();
  var skul_img2 = new Image();
  var skul_img3 = new Image();
  
  skul_img1.src = '/images/skul1-1.jpg'
  skul_img2.src = '/images/skul1-2.jpg'
  skul_img3.src = '/images/skul1-3.jpg'
  
  earth_image.src = '/images/earth.png'
  moon_image.src = '/images/moon.png'
  mars_image.src = '/images/mars.png'

  orion_image.src = '/images/orion.png'
  satellite_image.src = '/images/satellite.png'
  wall_image.src = '/images/wall.jpg'
  
  
  
  this.x = x;
  this.y = y;

  this.minZoom = 1.3;//1.3
  this.maxZoom = 1.3;//1.8
  this.zoom = this.minZoom;

  // var backgroundColor = Math.random()*360;
  var backgroundColor = 240;
	
	this.setupContext = function() {
		var translateX = canvas.width / 2 - camera.x * camera.zoom;
		var translateY = canvas.height / 2 - camera.y * camera.zoom;
		
		// Reset transform matrix
		context.setTransform(1,0,0,1,0,0);
    // context.fillStyle = 'hsl('+backgroundColor+',50%,25%)';
    context.fillStyle = 'rgb(0,0,0)';
		context.fillRect(0,0,canvas.width, canvas.height);

		context.translate(translateX, translateY);
		
		// Draw earth image before zooming
		
		context.drawImage(earth_image, -150, -150);
		
		context.drawImage(mars_image, -250, 1500);
		
		context.drawImage(orion_image, -250, -2000);
		
		context.drawImage(moon_image, 2000, -45);
		
		context.drawImage(wall_image, -2300, -200);
		
		context.drawImage(satellite_image, 2600, -800);
		
    // context.drawImage(skul_img1, -3000, -500);
    // context.drawImage(skul_img2, -2400, -500);
    // context.drawImage(skul_img3, -1700, -500);
    
		
    context.scale(camera.zoom, camera.zoom);
		
		if(debug) {
			drawDebug();
		}
	};
	
	this.update = function(model) {
    // backgroundColor += 0.08;
    // backgroundColor = backgroundColor > 360 ? 0 : backgroundColor;
		
		var targetZoom = (model.camera.maxZoom + (model.camera.minZoom - model.camera.maxZoom) * Math.min(model.userTadpole.momentum, model.userTadpole.maxMomentum) / model.userTadpole.maxMomentum);
		model.camera.zoom += (targetZoom - model.camera.zoom) / 60;
		
		var delta = {
			x: (model.userTadpole.x - model.camera.x) / 30,
			y: (model.userTadpole.y - model.camera.y) / 30
		}
		
		if(Math.abs(delta.x) + Math.abs(delta.y) > 0.1) {
			model.camera.x += delta.x;
			model.camera.y += delta.y;
			
			for(var i = 0, len = model.waterParticles.length; i < len; i++) {
				var wp = model.waterParticles[i];
				wp.x -= (wp.z - 1) * delta.x;
				wp.y -= (wp.z - 1) * delta.y;
			}
		}
	};
	
	// Gets bounds of current zoom level of current position
	this.getBounds = function() {
		return [
			{x: camera.x - canvas.width / 2 / camera.zoom, y: camera.y - canvas.height / 2 / camera.zoom},
			{x: camera.x + canvas.width / 2 / camera.zoom, y: camera.y + canvas.height / 2 / camera.zoom}
		];
	};
	
	// Gets bounds of minimum zoom level of current position
	this.getOuterBounds = function() {
		return [
			{x: camera.x - canvas.width / 2 / camera.minZoom, y: camera.y - canvas.height / 2 / camera.minZoom},
			{x: camera.x + canvas.width / 2 / camera.minZoom, y: camera.y + canvas.height / 2 / camera.minZoom}
		];
	};
	
	// Gets bounds of maximum zoom level of current position
	this.getInnerBounds = function() {
		return [
			{x: camera.x - canvas.width / 2 / camera.maxZoom, y: camera.y - canvas.height / 2 / camera.maxZoom},
			{x: camera.x + canvas.width / 2 / camera.maxZoom, y: camera.y + canvas.height / 2 / camera.maxZoom}
		];
	};
	
	this.startUILayer = function() {
		context.setTransform(1,0,0,1,0,0);
	}
	
	var debugBounds = function(bounds, text) {
		context.strokeStyle   = '#fff';
		context.beginPath();
		context.moveTo(bounds[0].x, bounds[0].y);
		context.lineTo(bounds[0].x, bounds[1].y);
		context.lineTo(bounds[1].x, bounds[1].y);
		context.lineTo(bounds[1].x, bounds[0].y);
		context.closePath();
		context.stroke();		
		context.fillText(text, bounds[0].x + 10, bounds[0].y + 10);		
	};
	
	var drawDebug = function() {
		debugBounds(camera.getInnerBounds(), 'Maximum zoom camera bounds');
		debugBounds(camera.getOuterBounds(), 'Minimum zoom camera bounds');
		debugBounds(camera.getBounds(), 'Current zoom camera bounds');
	};
};